Inverter-integrated electric compressors are used as compressors for air conditioners mounted on electric cars or hybrid cars. In the inverter-integrated electric compressors, an inverter accommodating section (an inverter box) is provided on the outer periphery of a housing that incorporates an electric motor and a compressor, and an inverter device that converts a direct-current power supplied from a power supply into a three-phase alternating-current power and applies the three-phase alternating-current power to the electric motor is incorporated therein. A rotating speed is variably controlled based on a control signal transmitted from a vehicle-side control unit (ECU).
The inverter device includes an inverter circuit composed of a power board on which a plurality of semiconductor switching elements (for example, IGBT) or the like that convert a direct-current power into a three-phase alternating-current power and apply the three-phase alternating-current power to the electric motor are implemented and a control board on which a control communication circuit such as CPU that controls the three-phase alternating-current power applied to the electric motor based on a control signal from the ECU is implemented, and a noise removing filter circuit provided in a power line that supplies a direct-current power to the inverter circuit. The noise removing filter circuit is formed by wire-connecting a plurality of electric components such as a head capacitor (a smoothing condenser), a normal mode coil, and a common mode coil.
In the inverter-integrated electric compressor as described above, in general, the inverter circuit and the noise removing filter circuit constituting the inverter device are collectively accommodated and installed in the inverter accommodating section (the inverter box) provided on the outer periphery of the housing, and are electrically wire-connected to each other through a bus bar to be incorporated therein (for example, see Patent Literatures 1 and 2).
Meanwhile, Patent Literature 3 discloses such a configuration that an inverter accommodating section in which an inverter device is accommodated and installed is composed of a lower case integrally molded with a housing of an electric compressor and an upper case coupled to the lower case and partially made of metal, and a circuit board where an electric circuit of the inverter device is provided, and electric components such as a coil and a capacitor constituting a noise removing filter circuit connected to the electric circuit are collectively accommodated and installed on the upper case side.